Here is what I did to get my first SATA II drive to work on a
GA-K8NXP-SLI board.

I went to www.giga-byte.com then went to the drivers page and selected
my board mode number. next I found the section listed SATA RAID Driver
and found my OS in the list and down loaded the drivers and then put
them on a disk.

on the system that I was putting together and started my os install,
in my case I did a system with 2K, when Windows shows a prompt for
press F6 to load third party SCSI driver do it and select the
appropriate driver and the proceed on.

During the Windows install it will ask you for the disk you put the
drivers on.

Hope this helps.

Lawrence